The CancerWeb Report, What's New In Cancer: December, 1996
Colorectal Cancer

• Further improvements in non-surgical treatment of cancer of the anus - Cancer of the anus is a relatively rare disease. New surgical techniques permit successful operations with minimum damage to normal rectal function. However, it is often impossible to surgically remove all the tumor while still preserving the functioning of the anal sphincter and so avoiding a colostomy. In many patients with disease that would otherwise require very radical surgery, results obtained with combined radiotherapy and chemotherapy (5-fluorouracil and mitomycin C) have been very promising. Should the disease recur, surgery is then still an option. A report by doctors at the National Tumor Institute in Milan, Italy, published in the December, 1996 issue of the Journal of Clinical Oncology, described the improved results they obtained in 35 patients with anal cancer for whom cisplatin was substituted for mitomycin C in the chemotherapy regimen. There was a complete remission rate of 94%, and after 37 months, 94% were alive and 86% did not require colostomies. Although these response rates were similar to those obtained using the original mitomycin-based chemotherapy, local recurrences were down from 24% to 6%, which represented a very significant improvement. (Doci, J Clin Oncol 14:3121, 1996)

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• News on the prognostic value of the DCC gene - The deleted in colorectal cancer (DCC) gene, as the name suggests is lost in many colorectal cancers. It may be a tumor suppressor similar to several others that have been identified. A group of researchers at Harvard, Yale, and Michigan Universities, and the Lahey-Hitchcock Medical Center, have tied the loss of this gene to a poorer prognosis in patients with colorectal cancer. They reported in the December 5, 1996 issue of the New England Journal of Medicine, that 5-year survival rates in patients with Stage II disease were 94.3% for those positive for DCC, compared with 61.6% for those without the gene. In the more advanced Stage III colorectal cancer, 5-year survivals were 59.3% and 33.2% for those with and without DCC, respectively. An important conclusion resulting from this finding is that patients with what appears to be Stage II disease, but who lack DCC, should be managed as if they were Stage III cases and given adjuvant treatment. (Shibata, New Engl J Med 335:1727, 1996)

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• A new predictor of relapse and survival in colorectal cancer - A potential new predictor of relapse and survival was reported by researchers at the Memorial Sloan-Kettering Cancer Center in New York, writing in the December, 1996 issue of the Journal of Clinical Oncology. They measured the nucleic acid (MMP-9 RNA) associated with an enzyme (a metalloproteinase) that helps tumor cells to digest their way through the structure of normal tissues and so to spread and metastasize. There was a mean increase of more than 9-fold in tumor levels of MMP-9 RNA versus those measured in normal colon tissue. Analysis of the data indicated that a more than 5-fold increase for a tumor sample was associated with a 9.5-fold increased risk of having significantly shorter disease-free and overall survival. The greatest differences in survival seen between patients with high and low MMP-9 RNA occurred in those cases with the higher risk Duke's C and D disease. (Zeng, J Clin Oncol 14:3133, 1996)